heating problems

[reeves]

My 1983 2.8. 6 Cylinder Skyline gt-x is giving me recently endless problems with heating. Heats only in traffic, but fine on the open roads. I've recored the radiator, checked the viscose fan, used coolant, still no luck. Could the oil pressure switch be causing all this, cause my oil\p & boost guages aint working no more, or could it be the timing cause I have put in a point system distributor and timing is continuosly going off { original dist broke].
Pls help with some suggestions, anyone, everyone.

[RazorGTR]

difficult to say honestly. I would suspect a thermostat in this case so far.

[Moppie]

Check the Viscos fan is actualy switching on, they are funny things, and Iv seen even new ones stop working for no known reason.

If it is working then start with the thermostat as Vince suggested, either replace it, or simply remove it and replace only if the problem goes away.

If all of that fails to fix the problem, then given the age of the car you have to start looking deeper.
Either a blown head gasket, clogged water way in the block, or failing water pump.

My first guess would be the water pump, as it ages it wears, and the impeller inside becomes less efective. At high way speeds there is enough air being pushed over the rad and engine that the laws of physics help cicrulate water between the cool radiator and the hot engine.
In traffic both heat up enough that the water pump is asked to do a job it simply can't.


A clogged water way is a little harder to find and fix.
As the engine ages rust flakes from the block and radiator will begin to accumulate in any tight spots in the engine. There is little you can do to remove them short of getting in there and stripping the engine down.
However removing the thermostat may allow a high enough flow of water that they will be dislodged, if you remove it make sure to keep an eye on the radiator, as they will block it up once freed from the engine. Simply removing the rad and back flushing it will clean it out though.
You can try back flushing the block, your engine is an old one, and should have somewhere in the side of the block a water drain plug. Take it off and stick a hose up there with as much presure behind it as your water main can supply. Take off both radiator hoses first and you should get some scale and rust out.


Finaly, it could be a blown head gasket.
It might be small leak, one that isnt showing up as water in the oil or vice versa. A compression test, or better yet a leak down test should find it.
But given you don't have any problems at speed I would put this at the bottom of the likely pile.


The other possiblity is due to a combination of any of the above the cooling system is simply not able to keep up with the demands of modern motoring, and the rise in global temps.
It might be time to invest in a proper electric fan to mount on the rad, and prehaps some ducting to improve air flow through it
Also make sure there are no air locks in the system, I doubt there are any bleed niples, but make sure you leave the cap off the rad untill the car has warmed up at idle after filling the system, and it should self bleed.


Good luck finding the problem though.


p.s. If the timeing is to advanced the engine will run hot, but it will occur at all speeds, not just in traffic. You can try retarding it and see if it makes a differnce.